| 摘要: |
| 为定量探索喷丸工艺参数对超声喷丸后材料表层残余应力场分布和硬化程度的影响规律，采用X射线衍射法研究了撞针式超声喷丸后7055T7751铝合金表层残余应力和半高宽的分布情况。结果表明：超声喷丸残余应力场分布深度（Zo）、最大残余压应力值(σmrs)及其深度(Zm)在一定范围内随冲击振幅(f)和撞针直径(d)的增加而增大。最佳工艺参数有两组，分别为2 mm直径撞针和80%冲击振幅、3 mm直径撞针和70%冲击振幅，两者使最大残余压应力分布深度提高1.31倍以上，且使材料冷作硬化层深度提高0.7 mm以上，并分别将最大残余压应力值提高到喷丸前的6.8倍和8.14倍。分析认为，超声喷丸对优化材料表面残余压应力场方面效果显著，适当强度的超声喷丸能够有效提高材料疲劳极限、表面冷作硬化程度。 |
| 关键词: 超声喷丸； 7055T7751 铝合金； 残余应力； 半高宽 |
| DOI：10.3969/j.issn.1007-9289.2014.02.013 |
| 分类号: |
| 基金项目: |
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| Residual Stress of Ultrasonic Shot Peened Aluminum Alloy |
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GUO Chaoya, LU Shihong
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College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016
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| Abstract: |
| To quantitatively explore the effects of peening parameters on surface residual stress distribution and hardening degree of shot peened materials, Xray diffraction method was adopted to analyze the distribution of surface residual stress field and halfwidth of diffraction peak of ultrasonic needle peening (UNP) 7055T7751 aluminum alloy, which provided a reference for UNP application and research. The results shows that the depth of the residual compressive stress filed (Z0), the maximum residual compressive stress (σmrs) and its depth (Zm) increase with the increase of amplitude of vibration (f) and diameter of needle (d); Two sets of optimum parameters are obtained, i.e. 2 mm in diameter of the needle with the 80% amplitude of vibration and 3 mm in diameter of the needle with 70% amplitude of vibration, which increase the depth of σmrs by more than 1.31 times and depth of the hardened layer by more than 0.7 mm, and σmrs increases by 6.8 and 8.14 times, respectively. UNP has great performance in optimizing material residual stress field, and can improve fatigue resistance and cold hardening degree of metal material with proper peening intensity. |
| Key words: ultrasonic shot peening 7055T7751 aluminum alloy residual stress full width at half maximum(FWHM) |
